<!DOCTYPE html>
<html lang="en">
  <head>
    <meta charset="UTF-8" />
    <meta name="viewport" content="width=device-width, initial-scale=1.0" />
    <title>Document</title>
    <style>
      #img1,
      #img2,
      #img3,
      #img4,
      #img5 {
        background-position: -7px -28px;
      }

      li {
        width: 20px;
        height: 20px;
        background: url(./star.png) no-repeat;
        display: inline-block;
        cursor: pointer;
      }

      .qh {
        background-position: -7px -8px !important;
      }

      p {
        margin-left: 40px;
        font-size: 24px;
      }
    </style>
  </head>

  <body>
    <div class="box">
      <ul>
        <li id="img1"></li>
        <li id="img2"></li>
        <li id="img3"></li>
        <li id="img4"></li>
        <li id="img5"></li>
      </ul>
      <p>0颗星</p>
    </div>
    <script>
      var ul1 = document.querySelector("ul");
      var p1 = document.querySelector("p");
      var lis = document.querySelectorAll("li");
      ul1.addEventListener("click", djFun);

      function djFun(event) {
        if (event.target.nodeName == "LI") {
          for (var i = 0; i < lis.length; i++) {
            lis[i].classList.remove("qh");
          }
          for (var i = 0; i < lis.length; i++) {
            lis[i].classList.add("qh");
            p1.innerHTML = i + 1 + "颗星";
            if (event.target.id == lis[i].id) {
              return;
            }
          }
        }
      }
    </script>
  </body>
</html>
